Bystanders thought they heard gunfire and fled; stores locked down.

Customers at Sacramento's Arden Fair Mall, crowded with after-Christmas sale shoppers, went into a panic when they heard loud sounds from a fight in the food court that sounded like gunshots.(Photo: KXTV-TV, Sacramento, Calif.)

That's when many customers in the mall, crowded with after-Christmas sale shoppers, went into a panic. The loud sounds from the fight echoed through the mall sounding like gunshots.

"Something similar to gunshots. We don't know if there was actually gunshots, but it did sound like shots," store employee Crystal Rocha said.

A gunman earlier in this month killed two and seriously injuring another before killing himself at a suburban Portland, Ore., shopping mall, heightening shoppers' awareness.

"You start thinking the worst thing that can possibly happen, like I just imagined someone with a gun or someone coming into the store and threatening us," shopper Ashley Ventura said.

"We hid behind a jewelry counter at Macy's, and then I was finally like, we need to get out of here. I'm not about to get shot behind a jewelry counter," shopper Samantha Lanni said.

Arden Fair Mall, Sacramento, Calif.

Mall Security Director Steve Reed said no gunshots were fired during or after the fight. Sacramento police said the sounds of large signs falling over may have led people to report shots fired.

Many stores went into lock down, closing their metal gates when the incident began.

The mall has 167 cameras constantly monitoring the mall in real-time, and security officers can be given radio instructions within moments of an disturbance. At least four off-duty Sacramento police officers were working at the mall when the fight broke out.